32-bit MCU's are starting to be used everywhere as things get more and more smart - NEST thermostat, for example. Just about everything these days would like to talk over the internet, or at least an internal network. This is much easier on the 32-bit devices.
Tom
http://www.mitydsp.com

ErrantOne, the 32-bit sleep state may not save you power, but you may save power by the 32-bit MCU needing to be awake for less time (ie, use fewer clock cycles) than an 8-bit in order to accomplish the task. With less on-time the average power goes down, even if the operating power of the 32-bit device is greater than the 8-bit.

4-bit microcontroller, I never use it. Which field it can be used? in children's toy?
Now, more and more project start to use 32-bit MCU, because the embedded linux operating sysyem need to port on it. The performance of 4/8/16 is not enough to support.

As devices get smaller it is sometimes more about electric power rather than number of bits. A few microamps saved here and there is important. If i can get 32bits and the power use of 8bits, then I'm interested. As it is, MCUs spend alot of time sleeping, depending on application. Tell me how 32bit MCU sleep state saves me more power......

The data and the article do not align:
16-bit ASP has declined from .71 in 2011 to a projected .53 in 2013. This is in contrast to 8-bit ASP of .65 and 32-bit ASP of 1.53 in 2013. At 41% of the forecasted unit volume, this is driving the ASP erosion.